Work-holding mechanism for lathes and the like.



W. T LINGO.

WORK HOLDING MECHANISM FOR LATHES AND THE LIKE-. 1,25%,7.

' APPLICATION FILED MAR. 10. IBIS- Patented Jan. 1,1918.

2 SHEETSSHEET1 li m l? W. T. LINGO.

WORK HOLDING MECHANISM FOR LATHES AND THE.L|KE.

APPLICATION HLED MAR. 10. I916.

Patehted Jan. 1,1918.

2 SHEETS-SHEET 2.

WILLIAM T...LI1\TGO,' 0F IHIL.AIDELPHIA,2PIEIN'NSYLVAJSI'IA.

WORKQHOLDING MECHANISM FOR LATHES AND THE LIKE.

' Specification of Letters Patent.

Patented Jan. 1, 1918.

Applicatio'n'filed March 10, 1916. Serial No. 83,416.

To all whom it may concern:

Be it known that I, \VILLIAM T. LINGo, a citizen of the United-States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful Improvements in Vv ork- Holding Mechanism for Lathes and'the like, of which the following is a specification.

This inventionrela'tes to lathes mechanism, and has particular reference to improved forms of mandrels and other work supporting devices. s

An objectof the invention is to provide a lathe with a mandrel which is rotatably supported at its opposite longitudinal extremities and, is further formed, in a novel manner, so that the sameis capable of being readily associated or disassociatcd with the driving mechanism of the lathe.

Another object resides in providing a mandrel with automatically operating gripping members which are adapted to engage the material to'be worked on in a firm and rigid manner, so that saidmaterial will revolve inunison with the mandrel and will be prevented from slipping when applied thereto.

A. further'object is to provide a mandrel with adjustable mechanism for receiving work of varying sizes Or diameters.

A still further object is the provision of mandrel for receiving bushing sleeves and the like, in order that the outer faces of the work may be machined or otherwise finished, means being provided for rigidly securing the work to the'mandrel and for cent'ering the same thereon so that the work may be quickly and accurately finishedu',

Other'objects reside in amandrel formed with mechanism for adjustingithe; work gripping elements'thereoii in a positive "manner so as to insure the rotation ofithe work in unison with the mandred.

The'invention further consists in im'proving and in enlarging the utility of the mechanism disclosed in my patent number 1,192,437, granted July 25, 1916..

In the further disclosure of the invention reference is to-be'had tothe accompanying drawings, in which similar characters of reference denote corresponding'parts in all the views, and inwhich:

Figure 1 is airagm'cntary side elevation of a lathe illustrating the preferred form of mechanism, comprising the present invention, applied thereto,

Fig. 2 is a vertical longitudinal sectional view of the same, I

Fig. 3 is an enlarged detail vertical sectional view illustrating the adjusting mechanlsrn for the work gripping elements,

Fig. 4 is a transverse sectional view in the line 4-4 of Fig. 1,

Fig. 5 is aside elevation, parts being shown'in section, of a slightly modified form of mandrel, 1 1 r Fig. 6 is a transversesectional view taken on the line 6--6 of Fig. 5,

Fig. 7 isan end elevation thereof,

Fig. 8 is a detail perspective view of one of the work gripping elements utilized in the form of the invention shown in Fig. 5,

1 Fig. 9 is a detail sectional view of one of the mandrel supporting heads, showing the removable lug members positioned therein,

Fig. 10 is a fragmentary section taken through the head stock center,

Fig. 11 is a perspective view of one of the removable lugs, I Fig. 12 is a transverse section through the tail stock center. v

Fig. 13 i a similar view on a difi'erent line,

Fig. 14.-is an enlarged sectional view on the line l515 of'Fig. 2. 7

Referring more particularly to the drawings, the invention is shown applied to the ordinary form of lathe B, comprising the usual bed 15, headstock 16, and movable tail-stock 17; the head stock 16 having-r0 tatably mounted therein the usual live spindle 18,.which is operated by the stepped pulleys 19 of conventional formation.

The free extremity of the live spindle 18 is provided with an inwardly tapered opening 20 for the reception of a similarly formed shank 21 of a mandrel supporting head 22, the latter being driven into the opening 20 so that the head will revolve in conjunction with the live spindle; A set screw 23 may be used to insure this feature. The member 22 comprises a conical head 24, integrally formed with the tapered shank 21, and in whichis generally formed an odd number of dove-tail seats 25, extending from the enlarged portion ofthe head to a point adjacent the extremity thereof. Securedly positioned in the seats are mandrel engaging lugs 26, formed Withbeveled faces 27 so as to provide relatively sharp" edges for vthe purpose of securing a positive grlp upontlieilvvall'so'f a'conica'l socket :28 formed" in a mandrel 29.

The mandre also provided with a conical shaped socket 2 and which s a apted-t0 rec ive. ch k support ng he d: "33 1 f; a design yslimllar'; to

the head 22. The head83 Consists of a'coniical'face 3e fvvhich is'inse'rted into thesocket 32 and said face is preferably provided with gripping lugs 35 oft-he same, construction as the lugs 26. j The othefrend of the head? is provided With an annular T shoulder 36 or and {anelon-gated shank-37, the latter being received Within a bOIeSSfD'nheClf in 'a stationary sleeve The bore 38 is of suflir: lcient'leng hto rec i r hc sl1an ;3 ;an 1s to accommodate the supporting dead center 40 of, a{-tailstook spindle 41,movable longitudinally of the bed '15 of'the'lathe B. The sleeve 39 is Wedged upon the center 40 so as to be rigidly supported thereby.

4 From the foregQingitwillbe evident that the inandrel29 Will be revolved through the agency .of the live spindle 18 and cooperating head 22, thisrotary movement being iinparted to theihead 33vand causlng the latter to revolve in lll'llSOHWl'I-ll the mandrel. This 7 feature, that is, a mandrelbeing' supported 7 between two rotatable centers, forms one of the salient features of the present invention,

as it perinits the mandreltorevolve smoothly and evenly on a true center; thereby permittingthe ork, supported by the'niandrel, to

be accurately and quickly accomplished to 1 .degree'unattainable'by a mandrel having but a single revolvingfcenter.

The mandrel is capable of quickly and conveniently placed in? operationandis accomplished by placing the'same upon the head 22,.[ivhen the latter 'is idle,flth'e tail stock j is then moved forwardly nn til the head is tightly wedged into the socket 32. This action results in, establishing 'a firm frictional contactbetween the head member :22 andthe socket; 28 and therebyrengleiging thedevi'cefit for operation; AHtlrfIlGtlOI-l avashers 42 are positioned between the head and/the'station-ary sleeve 39' in order'to eliminate friction or Wear at this-point of connection; A retaining screw a3 is threadied into the sleeve 39 and prevents the head 33' frorn becoming accidentally disengaged from the sleeve, the screw 43,. however, does not interfere with 'the rotation-ofthe head member '33-. r; I a A: The mandrel above described is particul ly- -arte o .i pper bu ngs s ves l 29 consists of air-enlarged head 30 and an elongated circular v i'nteg-'rallyfo'rinediv i th the headf- The end Of the mandrel 29 pposit th sevke fifi sbe y 1,.

and the like, although its usefulness is not limited to this particular class of Work, and a Work gripping mechanism is formed With the mandrel to engage in 'e'fiective'inanner to cause the same to revolve 1n synohronism V'With the mandrel 'andto prevent the same from slipping when being operated on, by

"the usual finishing tools.

Tothisend, the mandrel isformed with a loiig' itiidinal extending seat 45"opening into the outer periphery of the body thereof and in Which is movably positioned a rocking clutch bar i6,;. p-rov;i ded; on itsouter edgejvvith a -bev'efl'edj face47 The ends of e bar. are-prov ed wi t nnion ex ernsio' s t8 an a e i urn ed in peningsiea or face 47 of the bar 46 is normallyipositijoned Within the slots 50 but theouter nost d e. d e edxfae n rma y- "term fnates at a point below; the outer periphery of the s e t o al-purp e. t rifle ently-set'forth. ;Th e sleeve 49 v is one of a plurality of similarly shaped members,- but said membersvarywith respegt to theiriextreme; diameters, construction beingjnec- V .essaryto accommodate ork havingvaryingiii'ternaldiameters One of the trunn ons 48, te rini nates Within the enilarged head 30;of the finani t xend wiema w s o ma '52, and encircling the trunnien- -is a -helioal "spring 53 having one of its tern-finals secured to said trunnion hile the opposite extrem ty thereof 1s connected viththe gear 52. Thea-gear 5218' located Within: a bore ".54 form-eel in the head 9 @the ign andrel and "is adapted mesh with asimi-larggear er screw 55 ,rota tably connected. with an operating shaft: 516 theflatter extendingat right angles'to the trunnionii an d. being situated in a transversebore 57 Side cleats 53 cover the bore- 57 and areseeuredto theenla rg ed head 30 lay-means of fastening elements 58 said- [cleats being provided 1 with openings,

alin-ing. withth-e bore 5-7,. andae-ti-ngas bear- ,1

T er Xt m $9 he sa d are providedyvrth tool reeeivin g slots 60 in i rd-er that saidshaft "and: cooperatingjgear 55 may be; rotated. V

ingsfor the'reducedends 5 9 offheshaftbd In. operation, alsleeve or hushing idlfor other materialto be worked on, is positioned pon. the sleeve 4:9 surrounding the mandrel -29.- The mandrel isthen a-pplied to the conical head' member 24cfand the corresponda head 'me mb'er- 0 1; the moving head stock is brought into cooperation; with the Si 4 1 he byl ective r urp est mandrel and: associated membersv in an operative position. In order to lock the bushingorother work161-to the mandrel sothat the. inner periphery of-the; bushing 6 1,- th1 1s* insuring the rotation of the bushing -1n.

synchronism with the mandrel. By this construction the outer periphery of the bushing may be tooled or finished and also the faces of the ends thereof. A bushing having a tapered bore may be used in conjunction with the mandrel by forming the sleeve 49 with a corresponding taper to fit said bore, as will be obvious.

In the modified form illustrated in Figs. 5 to 8, a mandrel 65 is supported, as in the preferred form, upon the rotatable centering heads-2 and 33, the construction of which, having been previously described, will be omitted at this point. The mandrel 65, in this instance, is formed with radially extending slots 66 extending approximately one half of the length of the body thereof, and with intermediate bar receiving slots 67 adapted to receive work engaging clutch bars 68.

In operation, a bushing 69 is positioned upon the mandrel and the latter is then applied to the conical heads of the members 24 and 33. The action of the heads upon the mandrel will cause the latter to expand, which is permitted by the forming of the slots 66 therein, and this spreading movement forces the work engaging bars 68 into frictional contact with the bushing 69 with sufficient pressure to lock said bushing to the mandrel so that the former will revolve in unison with the latter. The mandrel is maintained in its expanded position by the action of spring pressed wedge members 70, positioned on the enlarged head 71 of the mandrel and having the beveled edges 72 entering the slots 66. When the bushing is desired to be released, the wedge members are lifted out of the slots 66 by eccentric members 7 3 so that the mandrel will be free to contract and thereby draw the bars 68 away from the bushing 69, so that the latter may be removed from the mandrel. It will be noted that the inner edges of the bars 68 are rounded longitudinally, as at 74, in

order to permit the bars to engage with work.

having a tapered bore.

In the modified form illustrated in Fig. 9 a bushing 7 5 is held between the supporting heads 2% and 33, the rotation of the bushing being governed in the same manner as that of the mandrel previously described. The usual mandrel is dispensed with in this form due to the fact that the bushing is smaller clutch bar extending lengthwise of said seat indiameter than the bushings. 61 and 69, and can be readily received uponthe rotatable heads 24 and 33.

The head members 24 and 33 may be provided with the lugs 26 .or the latter may be dispensed with if their utility is found to be unessential,.as will bethe casein certain instances. However, the lugs have been found to be extremely important when being used in" conjunction with the mandrels above described.

The mandrel is positive and eflicient in operation, of comparatively simple design and not liable to become out of order. The mandrel has been found to be of great value in machine shops as it permits work to be quickly placed in position and removed therefrom with rapidity hitherto impossible with the present forms of mandrels.

Having described the invention what is claimed as new, is,

1. A work holding mandrel, comprising a body having a longitudinal seat in the peripheral face thereof, a work gripping and adapted to rock therein to engage and release the work, means for imparting a rocking movement to said clutch bar comprising a shaft extending at a right angle to the longitudinal axis of the mandrel, and a gear actuated by said shaft and resiliently connected with said clutch bar.

2. A work holding mandrel for lathes, comprising a cylindrical body having centering sockets in the ends thereof, said mandrel body having a longitudinal seat in the peripheral face thereof formed with a rounded bottom, a work gripping clutch bar extending lengthwise of said seat and having a rounded inner edge and a beveled gripping edge, said clutch bar being adapted to rock in said seat to engage and release the work, means for imparting a positive rocking movement to said clutch bar, the last named means comprising a countershaft extendin at a right angle to the longitudinal axis 0 the mandrel, and a gear actuated by said countershaft and connected with said clutch bar, said gear being resiliently connected with said clutch bar.

3. A work holding mandrel for lathes, comprising a cylindrical body having centering sockets in the ends thereof, said mandrel having a longitudinal seat in the peripheral face thereof formed with a rounded 120 bottom, a work gripping clutch bar extending lengthwise of said seat and having a rounded inner edge and a beveled gripping edge, said clutch bar being adapted to rock in said seat to engage and release the work, 125 and a mandrel enlarging sleeve removably placed around said mandrel body and formed with a slot for said clutch bar.

4. A work holding mandrel for lathes, comprising a cylindrical body having cen- 130 i5z=barextendii1g lengthwise of said seat and f'ering stikets hi this erirls t hreof n'sai'd 'mailinner edge :fdnndfl' bdth:irfisxiifily ail id "drel body having a l'oiigjoudinalv seat in longitddina'llyz I v 10 the peripheral face thereof fbrrhed with a ln tsti'inony wherdf lm fix mys igna t u'i'e V rounded bottbm, and a workvgrippingcl-utch ifi presnce oftwd witness'sz V .7; V

I WIIJLIAM BEN-G6; .having' a beveled gripping edge, said clutch 'Witnessm... .1 1

bar being adapted to rock in Said seat .to ex)- EM IL PIZZA-g I gage and relea'se the Work and having its v.Imxna: RA-132s. 

